Lifting mechanism for dump bodies



w \Q 43 Q mm mN R \\m x5 S o m y n We May 27, 1930. F. BISZANTZ LIFTINGMECHANISM FOR DUMP BODIES Filed Feb. 25, 1930 y 1930- F. BISZANTZ1,760,808

LIFTING MECHANISM FOR DUMP BODIES Filed Feb. 25, 1930 2 Sheets-Sheet 241-77 I I g /6 gmwntoz Z3 FIH LZ' Biszan Zz .i wm

Patented May 27, 1930 UNITED STATESPATENT OFFICE FRED BISZAN'IZ, OFGALION, OHIO, ASSIGNOR TO THE CENTRAL OHIO STEEL PRODUCTS GALION, OHIO,A CORPORATION OF OHIO COMPANY, OF

LIFTING MECHANISM FOR DUMP BODIES Application filed February 25, 1930.Serial No. 431,817.

This invention relates to hydraulically actuated dump bodies andparticularly to the means whereby the motion ,of the hydraulicallyactuated piston is translated into a lifting motion exerted beneath thedump body to tilt it.

One of the objects of the present invention is to provide a liftingmechanism of this character wherein all of the parts of the assembly aredisposed above the chassis or frame of the motor truck so that all ofthe mechanism is-easily adapted to all makes of trucks.

Another object is to so connect the body to the hoisting mechanism thatno lurching of the truck with the body partly hoisted can pull it awaywith a consequent rapid downward movement and crash of the body.

A further object is to provide a mechanism of this character which willinitially start the lifting movement of'the body by means of arelatively short levercompensating for the fact that at this point thegreatest work must be performed and the greatest strain is involved andin this connection to provide a mechanism of this character, which afterthe body is tilted and the center of gravity is shifted toward the rear,the lifting point will shift to accelerate the speed of the lifting andin efiect secure the use of a longer lever, this mechanism operatingstill later to secure a still longer leverage action.- 1 7 Anotherobject in this connection is to provide a lever and link mechanismacting to-lift the bodywhich will prevent any excessive amountof-lostmotion between the lever and body and which is so constructedthat the lever cannot arrive upon a dead center, and in which the travelof the levers is at a uniform speed from start to finish.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawings, wherein:- I

Figure 1 is a side elevation of a portion of the chassis or supportingframe of a truck and the body and showing in dotted lines the bodylifted to its final tilted position;

tion shown inFigure 1;

Figure 3 is a cross section through the lifting cylinder and alliedparts.

Referring to these drawings, 10 designates the sub-frame mounted on anysuitable or usual truck A. The body is designated 11 and this body ismounted upon a frame consisting of longitudinal elements 12 connected bytransverse members 13. The body is operatively pivoted to the truck bymeans of lugs 14 riveted, bolted or otherwise attached to the elements12 and extending down below the same and pivotally engaged with thesubframe 10 as shown in Figure-1, the pivot being designated 15. It willthus be obvious that the body' can tilt'from the full line position inFigure 1 to the dotted line position.

For the purpose of dumping the body, I provide a hydraulic cylinder 16,one end of whichis connected by means of a pipe 17 and suitableconnections to a pump such as the rotary pump quite usually used inconnection with these hydraulic dumping trucks. Within the cylinder,there is disposed a piston, the piston rod 18 of which extends out overthe rear end of the cylinder andis connected to the cross head 19. Thiscross head extends transversely of the length of the truck. While I donot wish to be limited to the use of any particular means for mountingthe cylinder 16 upon the sub- .frame 10, I have extended the reduced end20 of the pipe 17 or an equivalent element through a transverse bar 21,this transverse bar being an gularly bent at its ends and being riveted,bolted or otherwise attached to longitudinal plates 22, theseplatesbeing suitably braced, the rear ends of these plates 22 being connectedto the angular ends of a yoke 23 upon which the cylinder 16 is adaptedto seat as shown in Figure 3. The cylinder 16 is held upon the seat ofthe yoke by means ofa hoop 24 which partially'surrounds the cylinder andhas its ends extended through openings in the yoke 23 and these endsengaged by bolts 25. Fixed shaft 33 extends through plates 22.

The yoke 19 is laterally extended as before stated and. has forwardlyextended bifurcated extremities 26 to which the end links of chains 27are pinned as at 28. These chains 27 extend forward and downward andpass over sectors 29. These sectors are con nected as by the integrallateral extensions 30 to arms or levers 31, each arm or lever beingangularly bent so that the outer end of the arm extends downward andforward when the arm is in its initial or retracted position. Each ofthese levers is integrally cast with or otherwise connected to a tubularshaft or sleeve 32, these shafts or sleeves being mounted upon a fixedtransverse member 33 which constitutes a trunnion for each end of theshaft 32 and engaged in bearings 34 which are attached to the sub-frameelements 10.

The cylinder extends upward and rearward. The ends of the chains areattached to the forward ends of the sectors 29 in any suitable manner.The chains are held from lateral movement on the sectors by means of thelugs 35 or other suitable means. It will be obvious now that when fluidis pumped into the forward end of the cylinder 16, the piston (notshown) therein will force the piston rod outward, forcing the cross headrearward, drawing upon the chains 27, causing a rearward rotation of thesectors 29 and causing the levers 31 to move upward and rearward fromthe full line position in Figure 1 to the dotted line position in Figure1.

The levers 31 are preferably formed as illustrated in Figure 2 of twospaced portions connected by spacing elements 36, 37 and 38 whichconstitute pins co-operating with a link designated generally 39 whichwill now be described.

There are two links, one on each side of the body. They are connected tothe body in any suitable manner, as for instance, to cars 40 mountedupon the beams 12. Each link is pivoted at its upper end to thecorrespondin ear 40 as by means of the trunnion 41. Eac link is widenedat its lower end and formed with an angular slot 42, the arms of thisslot being acutely angled with relation to each other.

Rearward of this slot, the under face of this link is formed with a seat43 for the pin 36. The lower wall of the slot is formed with the seats44 and 45 for the pins 37 and 38 respectively. The rear leg of the slotis formed with the seat 46 for the pin 37 and the forward end ofthe slot42 is formed with a seat 47 for the pin 38. The lower end of each linkis disposed between the two members forming the lever 31. The pins 37and 38 are disposed through the slot 42 while the pin 36 is disposedbeneath the seat 43 in the initial position of the parts. I

In the initial position of the parts, the pin 36 is disposed against theseat 43 of the link. Upon an initial movement of the cross head 19, anda consequent initial movement of the sectors 29, the pins 36 will liftupward on the links 39, the lifting point being relatively close to theaxis of the levers 31 and to the point of application of power to theselevers. The upward movement of the levers 31 starts the body upward bylifting against the seats 43 of the links. This gives the effect of ashort lever for use at the time when the load is heaviest. After thebody is tilted a certain distance and the center of gravity has traveledsomewhat toward the rear of the body, the pins 37 reach the seats 46 andthe effective length of the levers 31 is thereby increased by thedistance between the lifting points or pins. This accelerates the speedof the lifting by the use of a longer lever. Upon a further movement ofthe parts, the pins 38 come into engagement with the seats 47 and thepins 37 move relatively downward and forward so that eventually theparts have the position shown in dotted lines shown in Figure 1 wherethe pin 37 is disposed in the seat 45, the pin 37 being disposed againstwhat may be termed the forward wall of the slot at its lower end and thepin 36 being disposed entirely below the link and out of engagementtherewith. This acts to still further accelerate the movement of thebody as the lifting becomes easier due to the center of gravity of thebody moving rearward.

At this time, the middle lifting pin 37 as shown in dotted lines inFigure 1 prevents any excessive amount of lost motion between the leverand body and the two lifting pins 37 and 38 acting in unison within theslotted link, prevent the three points, 33, 41 and 38 arriving at a deadcenter. Upon a downward movement of the body, of course, the reverseaction takes place.

At the first part of the movement, the links rest upon the pins 38,until the pins 37 move up into the seats 46. Then these pins 37 take theweight of the body and then the pins 36 take the weight of the body andthe parts come to the position shown in Figure 1.

It will be seen that I have provided, therefore, means for operating andengaging the lifting arms or levers 31 with the body, initially at apoint inward of the ends of said arms when the arms are in a horizontalposition and then as the arms and body rise, shifting the point ofoperative engagement rearward toward the pivotal axis of the arms. It isalso to be noted that I secure a uniform rotation of the tubular shaftor sleeve 32 upon which the arms are mounted by reason of the fact thatthe curved faces of the sectors 29 are drawn on a true radius from thecenter of sleeve 32 or axis 33. Consequently the travel of the leversand sectors is at a uniform speed from start to finish with noacceleration inthe movement of rotation, but I secure an acceleration ofthe speed of the lifting by initially using a short lever, then using ineffect a longer lever and then using in efmenses feet a still longerlever. Furthermore, it will be seen that as the lever is used, the pointof application of the lever to the dumping body shifts toward the centerof rotation of the dumping body, that is, the trunnions 15. It is to benoted also that the two lifting points or pins 37 and 38 toward the endof the lever act in unison within the slotted link as shown in dottedlines in Figure 1 to prevent the three points formed by the pins 36, 37and 38 from arriving at a dead center and that While the final liftingis being done the pin 38, the middle lifting point formed y the pin 37prevents any excessive amount of lost motion between the lever and thebody.

The mechanism which I have devised keeps all parts of the liftingmechanism above the frame ofthe motor truck so that themechanism iseasily adapted to all makes of trucks. The body is at all times soconnected to the hoisting mechanism that with the body partly hoisted,no lurching of the truck can pull the lifting mechanism away from thebody with a consequent release of the part from the lifting body. Thelink and the lever form a stop preventing any movement to or past thedead center and thus the body will always return to its normal positionas soon as the lifting force is released. The lifting levers do notproject below the frame. This is par ticularly desirable as it greatlyreducesthe number of types of hoists necessarily carried by dealers tofit all makes of trucks. The cylinder, in my construction, is disposedin such position-that the force exerted by the piston thereof is in thesame general direc tion as the movement of the body, thus securing highefficiency.

It will be understood, of cou'rse, that the.

pipe 17 is to be connected to a rotary'pump as is usual'in thesehydraulic hoists, that this pump draws fluid through a pipe 17 from thefront of the piston, and forces this fluid into the pipe 17 behind thepiston. When the piston arrives at the rear end of the cylinder, itpasses the end of pipe 17 a and the movement of the piston stops and ifthe pump continues to run, fluid will pass through the cylinder and willbe again returned to the pump. If the pump benow stopped, the pistonrod'will settle back a short distance and the body may be held in anyposition until a valve or valves be shifted to connect the out-put portof the pump with the forward end of the cylinder and thein-put end ofthepump with the rear end of the cylinder to permit a reversemotion ofthe liquid within the cylinder or certain valves operate to permit thereturn of the piston under the weight of the .body.

This mechanism is, therefore, not limited .to the use of any particularpumping means or anyparticular valve means for'controlling the flow offiuidinto or from the cylinder. Such a valve means, however,is disclosedin my pending application for patent, Serial $35131 ,318, filed on the25th day of February,

Obviously many minor changes might be made in the details ofconstruction without departing from the s irit of the invention asdefined in' the appen ed claims.

I claim 1. Ina dum ing truck, a supporting frame, a dumping bo ytiltable on the frame, a shaft on the frame, means for causing rotationof the shaft in one direction at'a uniform'speed, lifting arms carriedby the shaft, means car'- ried by the body and shiftable with relationthereto with which said arms engage, and means for engaging the armswith said means initlally at a point inward of the ends of said armsWhen the arms are in a horizontal position, and then as the arms andbody rise, 'shiftlng the point of operative engagement away from thepivotal axis of the arms and simultaneously shifting said means towardthe pivotalaxis of the body.

2. In a dumping truck, a supporting frame, a dumping body tiltablymounted on the frame, a shaft mounted on the frame, means the point ofengagement of the links and arms away from the pivotal axis of the arms.

3. In a dumping truck, a supporting frame,

adumping body tiltably mounted on the frame, a shaft mounted on theframe, means for causing the rotation'of the shaft in one direction,lifting arms carried by the shaft, links pivotally engaged with the dumpbody for free swinging movement in a vertical plane, each link having aplurality of seats,

the arms having a plurality of fulcra successively engaged with saidseats as the arms rise, said fulcra being arranged at successivelyshorter distances from the axis upon which the arms turn.

4. In a dumpingtruck, a supporting frame, a dumping body tiltable on theframe, a shaft mounted on the frame, means for causing rotation of theshaft in one direction, lifting arms carried by the shaft, linkspivotally mounted upon the body and depending therefrom, each of saidlinks having a plurality of seats, each of said arms having a pluralityof pins projecting laterally from the arms, and adapted to successivelyengage said seats as the arms are raised, the pins nearest the center ofmotion of the arms initially engag ing their seats in the links, thepins next in order then successively engaging their seats and the pinsadjacent the extremitiesof the arms finally engaging their seats in thelinks as the arms are raised.

5. In a dumping truck, a supporting frame, a dumping body tiltable onthe frame, a shaft mounted on the frame, means for causin rotation ofthe shaft in one direction, li ting arms carried by the shaft, linkspivotally mounted upon the body and depending therefrom, each of saidlinks having a plurality of seats, each of said arms having a pluralityof pins projecting laterally from the arms, and adapted to successivelyengage said seats as the arms are raised, the pins nearest the center ofmotion of the arms initially engaging heir seats in the links, the pinsnext in order then successively engaging their seats and the pinsadjacent the extremities of the arms finally engaging their seats in thelinks as the arms are raised, the final movement of the arms acting toengage two of said pins with two of the seats in the links to therebyprevent the point of engagement of the last named pin with the link frommoving to a position of dead center with relation to the pivotalconnections of the links and the rotative axis of the arms.

6. In a dumping truck, a supporting frame, a dumping body tiltable onthe frame, a shaft on the frame, means for causing the rotation of theshaft, lifting arms carried by the shaft and having a plurality oflaterally projecting pins, the pins being arranged in a line from apoint adjacent the extremity of each arm toward the center of motion ofthe arm and links pivotally mounted upon the dump body, each link havingan angular slotwithin which two of said pins are at all times disposed,the slotbeing formed with seats for said pins, and the exterior wall ofthe link being formed with a seat for that pin which is nearest thecenter of rotation of the corresponding arm, said pins successivelyengaging in said seats as the arms are lifted from the innermost pin tothe outermost pin.

7. In a dumping truck, a supporting frame, a dumping body tiltable onthe frame, a shaft on the frame, means for causing the rotation of theshaft, lifting arms carried by the shaft and having a plurality oflaterally projecting pins, the pins being arranged in a line from apoint adjacent the extremity of each arm toward the center of motion ofthe arm and links pivotally mounted upon the dump body, each link havingan angular slot within which two of said pins are at all times disposed,the slot being formed with seats for said pins, and the exterior Wall ofthe link being formed with a seat for that pin which is nearest thecenter of rotation of the correv ponding arm, said pins successivelyengaging in said seats as the arms are lifted from the innermost pin tothe outermost pin, each slot being formed with a seat with which the pinadjacent the outermost pin engages when the outermost pin is inengagement with its seat, and the arms are lifted to their full extentwhereby to prevent the link from swinging to a position of dead center.

8. In a dumping truck, a supporting frame, a dump body tiltable on theframe, a shaft carried on the frame and having sectors mounted thereon,flexible elements passing over said sectors, a cylinder having a pistonand a piston rod, the piston rod being operatively engaged with saidflexible elements to cause a rotation of the sectors and shaft when thepiston is forced outward, lifting arms mounted upon the shaft androtating therewith, and links pivotally mounted upon the dump body anddepending therefrom, a plurality of seats formed upon said links, aplurality of pins carried by said arms and adapt ed to successivelyengage said seats, the pins being disposed in spaced relation from theextremity of each arm toward the pivotal axis thereof, the innermost pinon each arm first engaging its seat in the respective link and the pinssuccessively engaging their seats as the arms rise.

9. In a dumping truck, a supporting frame, a dump body pivotally mountedupon the frame for tilting movement, a cylinder mountedupon thesupporting frame beneath the dump body and having a piston and pistonrod, a cross head mounted upon the extremity of the piston rod, thecylinder being disposed in an upward and rearward direction, a shaftmounted upon the supporting frame and carrying sectors of uniformradius, flexible elements connected to said sectors and to the crosshead whereby as the cross head moves rearward, the sectors will berotated, lifting arms mounted upon the shaft and normally extendingforward therefrom and provided with a plurality of pins arranged inorder from the extremity of each arm toward the center of motionthereof, and links pivotally mounted upon the dump bod and having aplurality of seats, one for eac of said pins, the pin nearest the shafton each arm engaging the seat nearest to the pivotal axis of thecorresponding link, initially as I the arm rises. and the pinssuccessively engaging the successive seats as each arm moves upwardtoward its highest position whereby to shift the point of operativeengagement of the arm with the dump body from a position relativelyadjacent the center of motion of the arms to a position relativelyfurther away from the center of motion of the arms.

In testimony whereof I aflix my signature.

FRED BIbZANTZ.

